The acquisition of the NMR signal is the last step in any NMR experiment. During this period, the NMR signal is recorded in the time domain as a free-induction decay. When acquire an heteronucleus signal different to ¹H, for instance ¹³C, we have different possiblities. When no ¹H decoupling is applied, full information about homo- and heteronuclear NMR coupling constants are obtained.

Other ¹³C acquisition schemes are available:

• With ¹H-decoupling 
• With selective ¹H-decoupling 
• With ¹H,Y-decoupling 

Easy implementation on AVANCE spectrometers.

 For more experimental details see Tutorials: Calibration pulses.

The standard way to implement a ¹H acquisition period is:

... 2 d1 cpd2:f2 ... go=2 ph31 do:f2 ...

in which:

• go starts data acquisition during an acq period using the acquisition parameters previously defined in eda.
• The number after go (=2) defines the loop to be executed. The number of scans (ns) defines the number of times this loop is repeated.
• ph31 is the receiver phase specified at the end of pulse program and must be cycled in accordance to all pulses involved in the pulse sequence.
• The do:f2 command (decoupler off) is necessary if ¹H-decoupling (see cpd2:f2 command during the d1 period) has been operative previous to the acquisition period.